Gas solid contact



Feb. 2, 1960 BRAUNL1CH 2,923378 GAS SOLID CONTACT Filed April 5 1955Unitcd Statcs Patent GAS SOLID CONTACT Richard H. Braunlich, WestChester, Pa. assignor to American Viscose Corporation, Philadelphia, Pa.a corporation of Delaware Application April 5, 1955, Serial N0. 499,321

5 Claims. (Cl. ISS-114.2)

This invcntion rclates to an extruded monofilament containing an inertmaterial and, more particularly, to a pellct-like particle or waferformed by cutting or slicing an cxtrudcd monofilament into predeterminedlcngths.

In accordance with the present invention, I have found that it ispossible to extrude through a suitable spinneret or jet a monofilament,prefcrably of greater than 50 denier, in which a material suitable forusc in various types of. chemical proccssing equipment is bound. Thevehicle or binder used in the present invention is proferably cellnlosicsuch as viscose but may bc any extrudable materifl such as celluloseacetatc or nylon that can be conveniently and economically employed inthe process. Such materials may be polymeric, thermosetting orthermoplastic. The present invention will be described primarily asemploying a viscose monofilament in which the material which should beinert to the viscose may bc in thc rangc of 25-95% on the basis of thesellulose in the viscosc. Under other conditions the inert material maycomprise from 1595% by weight of the final product. Such pellets orparticles aftcr regeneration are of great ntility in adsorption orcxtraction columns, ion-exchange columns, chromatography and catalystbeds for liquid and gas hase reactions. Any solid which may hepelletized for use in chcmical processing cquipment can be incorporatedin the prcscnt invention in accordance with the particular type ofapparatus and proccss for which it is intended. Such a material will bereferred to gencrally as the inert material to distinguish it from thebinder or vchicle. It will be understood, howcver, that this inertmaterial need only be inert to the particular binder employcd and thctypc cf regeneration or setting i1p that may bc rcquired under thecircumstances. Since t.he nozzle or spinneret holes would preferably bcon the order of one-sixtcenth to onc-eighth of an inch in diameter or ofa shape providing a corresponding area, the inert material may becomparativcly large without dangcr of plugging thc spinneret holes. 011the other band, the present invcntion permits thc use of extremelyfinely ground material where such is desirable since the extrudedmonofilament can be regenerated with or without acid by means of a hotwater bath, a salt bath, an acid bath or bot gas such as air, steam ornitrogen. With hot gas, an aging accclerator may be incorporated in themixture before cxtrusion.

A particularly imp0rtant featurc of the present invention resides in thcability to provide a relative porous pallet or disc which in turnpermits complete enetration of thc fluid in the bed. The pellcts areamorphous and will expand like tiny sponges to permit complete difiusionof liquid or gas through the individual pcllets. This represents adistinct advancc over the convcntional pallets supplied for usc inchemical apparatus because only surface contact with the pelletizedmaterial has been possible. Furthermore, the movernent of theconventional pellets tends to permit small particlcs or fines to breakoft. These are carried along with the gas or liquid so that iurthertreatment to remove the fines is fre- "ice 2 quently required. Inaddition, many useful catalysts cannot be pelletized in the conventionalmanner but can be incorporated in the pellets of the prcsent invention.

A primary object of the present invention therefore is to provide animproved pellet for use in chcmical proccssing equipment.

A further object of the invention is to provide a porous pellet for usein chemical processing equipment.

A still further object cf the invention is to provide an improved porouspcllet having a cellulosic binder.

A further object 015 the invention is to provide a method for producinga uniform particle or pellet which may be packed into a controlledstructure having use in catalyst beds and ion-cxchange beds.

A further object of the invention is to provide an improved pellet f0rchemical processing beds in which the fincs are completely bound.

A further objcct of the invention is to provide an improved method forproducing accurately a plurality of pellets having identical amounts ofnon-cellulosic material.

A further object of the invention is to provide a method for producingcellulosically bound monofilaments.

Further objects will be apparent from the specification and drawings inwhich:

Figurc 1 is adiagrammatic showing of the apparatus for forn1ing a largemonofilament in accordance with the present invention;

Figure 2 is a diagrammatic perspcctive showing a cutter for making smallwafers or pellets from thc monofilamcnt formed as shown in Figure 1;

Figure 3 is a perspective showing on an enlargcd scale onc of thepellets.

The invention comprises essentially the formation of a relatively largemonofilament cxtruded into a liquid bath to sct up a cellulosic vehiclein which a material useful in some chemical process has been injected.The monofilarncnt can be sliced or chopped into small sections ofuniform length so that the quantity of the material in cach pellet isaccurately known. Preferably, thc filament can be regenerated withoutacid and the material carried by the cellulosic binder would be choscnso that it would be inert to the particular regeneration bath employedas well as inert to the viscose. Examplcs of such materials areabsorbent or adsorbent carbon black, catalysts such as Fe O Mg0, Cr Oand aluminurn oxides; in fact, any material which is uscful inadsorption or extraction columns, ion-exchange columns, chromatography,catalyst beds for liquid or gas phase reactions. The use of thc largeextrusion orificc perrnits nearly any solid which is customarilypelletized for use in chemical proccssing to be bound in the cellulosemonofilament and the regeneration bath would be chosen accordingly.

Referring now more particularly to the drawings, a

monofilament M is formed by extruding a mixture of liquid cellulosicvchicle such as viscose and the desircd inert material through aspinneret 5 into thc regenerating bath 6. 'I-he filament is carried fromthe bath 6 0ver a guide 7 whereupon it may be wound up or stoied in anydesirable manncr or after suitable washing may be directly sliced orpelletized. The monofilament M in Figure 2 may be fcd into any slicingmachine along a guide 8 and through a plate 9. A revolving blade 10 cutsofi or slices predetermined lcngths cf the filamcnt M to form the wafersor pellets P such as shown in Figure 3. The blado 10 is rotated by meansof shaft 11 connectcd to a suitable source of power not shown.

It will be understood that the pellets formed as described above willhave uniform distribution of the material carried in the binder. Thiswill be the case even though cxcessive grinding is not required beforeextru-.

sion through the spinneret er jet 5. Such pellets or wafers can becounted or weighed to obtain an accurate calculation of the amount ofmaterial contained in any given. nunaber or volurne. They eine seful inadsorption columns; for example; activated ca'rb'on in the pellets c2in.be*used to adsorb ammonia fr'dm gas strezims. In the liquid'phase, theymay be used fd removd rganic materia'l dissolved in water and in packedbc':ds for .any type of liquid phase extraction. Ion-exchange ai1dchr0-matography are other fields which find use for such peiletized material.Generally these uses invo1ve packed beds through which various fluidsare passed.

A particularly noteworthy field for the products of the presentinventioaare in catalyst beds for both oiganic and inorganic rea :tions.- Thesereactions include synthesis, decomposition, hydration, dehydration;reduction, oxidation, hydrogenation, dehydrogenaticin, chlorination,dechlorination, bromination, fluorination iodinatibn, nitrogenation,denitrogenation, sulfurization, desulfuriztion, alkylation, destructivealkylation, condensation, polymerization, isomerization and cyclization.

Particular benefits to be derived in the practice of the presentinvention include the ease and W cost of forming the large monofilamentsand the pellets. Since the porosity of the bed can be accuratelycontrolled by practicing the present invention, i. follows that thepressure drop through the beds can also be controlled' ai1d thusundesirable high pressure drop can be avoided; Precise quantity of theinert material present in the bed is capable of accu rate control. Themais no d3nger that the particles cf the catalyst will be carried out withthe gas er liquid when the pellets are used in the gas or liquid phase.It will be understood that the cross-sectional shape of the monofilamentmay take any desired form such as round, flat, squareetc. The termpellet used in the specification and claims is ihtended to include anythickness of the severed porti0n of the monofilament whether a very thinwafer-like size on up to rods or bars.

Having thus described my invention, 1 claim:

.1. A process of contacting a fluidwith acontact agent selected from thedass consisting of catalysts, absorbents and adsorbents, said contactagent being uniformly distributed in a packed bed cf a contact materialthrough which the fluid is passed, the contact material being in theform of monofilament sections having a cellulosic body, with particlesof the contact a'gent distributed uniformly within and forming anintegral part of said monofilament sections.

2. Process of' claim 1 whereiri the Contact agent is carbon black.

3. Process of claim 1 wherein the contatt agent is a metal oxide.

4. Process of claim 1 wherein the panticles cf contact agent comprise'2595% by w'eight of the monofilament.

5. A process for removing ammonia from a gas stream by passing said gasstream through a column cf contact material containing activated carbonwhich seleetively adsorbs the ammonia, the contact materi'al bein'g inthe form of cellulos ic monofilarnent sections having a cellulosicbod'y, with fine1y divided. particles of activated carbon distributeduniformly within and forming an'integral part of said monofilamentsections.

FOREIGN PATENTS 655,185 Great Britain Ju1y 11, 1951 y OTHER REFERENCES NAdsorption, by C. L. Mantell, McGraw-Hill Bock Co., Inc. New York, 1945,firstedition, page 12.

1. A PROCESS OF CONTACTING A FLUID WITH A CONTACT AGENT SELECTED FROMTHE CLASS CONSISTING OF CATALYSTS, ABSORBENTS